<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<meta name="Generator" content="Microsoft Exchange Server">
<!-- converted from text --><style><!-- .EmailQuote { margin-left: 1pt; padding-left: 4pt; border-left: #800000 2px solid; } --></style>
</head>
<body>
<div>You could have the same URL resolve in DNS to the "local swift" in each region or you could use anycast. <br>
<br>
<br>
-------- Original message --------<br>
From: Sam Morrison <sorrison@gmail.com> <br>
Date: 05/19/2013 8:39 PM (GMT-05:00) <br>
To: Jay Pipes <jaypipes@gmail.com> <br>
Cc: openstack@lists.launchpad.net <br>
Subject: Re: [Openstack] Share Glance between cells or regions <br>
<br>
<br>
</div>
<font size="2"><span style="font-size:10pt;">
<div class="PlainText">Hi Jay,<br>
<br>
We are doing something similar. We have a single glance registry which is backed by galera DB replication.<br>
Then we have multiple glance-apis around the place.<br>
<br>
Currently they are all backed onto the same swift but I'd like to have it so each glance-api can talk to it's own swift.<br>
The issue I see is that the location of the image as stored in the glance-registry is a keystone url.
<br>
So yes you could get a glance api to store data in a specific swift region (using the swift_store_region) but it has no way of knowing which region to pull an image out of.<br>
<br>
I think the location value stored when using swift needs to be the swift URL or else it needs to store the region in the DB too.<br>
<br>
Have you thought about this? Have a solution?<br>
<br>
Cheers,<br>
Sam<br>
<br>
<br>
On 16/05/2013, at 6:49 AM, Jay Pipes <jaypipes@gmail.com> wrote:<br>
<br>
> On 05/15/2013 02:46 PM, John Paul Walters wrote:<br>
>> Hi,<br>
>> <br>
>> We're looking at setting up a geographically distributed OpenStack installation, and we're considering either cells or regions. We'd like to share a single Glance install between our regions (or cells), so the same images can be spawned anywhere. From
here:<br>
>> <br>
>> <a href="http://docs.openstack.org/trunk/openstack-ops/content/segregate_cloud.html">
http://docs.openstack.org/trunk/openstack-ops/content/segregate_cloud.html</a><br>
>> <br>
>> it's not clear whether that's possible. Can anyone shed some light on this? Is it possible in regions OR cells (or both)? Is there a better solution that I'm not thinking of?
<br>
> <br>
> We will be sharing both the Keystone identity (note: not token/catalog)<br>
> and Glance registry databases in a synchronously-replicated Galera MySQL<br>
> cluster. Databases like the above, which have extremely low write to<br>
> read ratios are ideal for this kind of replication. We are replicating<br>
> working sets over the WAN using rsync replication in the WSREP<br>
> clustering software.<br>
> <br>
> What this enables us to do is have a single set of account records and a<br>
> single set of image (base and snapshot) records. Note that we back<br>
> Glance in each zone with a zone-local Swift cluster. But what this<br>
> allows us to do is have a user in zone A make a snapshot and then<br>
> immediately (once the snapshot goes from the SAVING state to ACTIVE),<br>
> the user is able to launch their snapshot in zone B. The Glance registry<br>
> database has the location of the snapshot in zone A's Swift cluster and<br>
> when Nova in zone B launches the image, the Glance API server in zone B<br>
> simply pulls the image bits from Swift in zone A.<br>
> <br>
> Best,<br>
> -jay<br>
> <br>
> p.s. I say "will be sharing" because we are currently updating our<br>
> deployment to use this single Glance registry database. Originally we<br>
> went down the route of each zone having its own Glance registry database<br>
> and realized that since the pattern of write activity to the Glance<br>
> registry is so low, it made sense to replicate it across our zones and<br>
> give the users the ability to launch instances from snapshots in any<br>
> zone. The single identity database is already in use across our zones.<br>
> <br>
> _______________________________________________<br>
> Mailing list: <a href="https://launchpad.net/~openstack">https://launchpad.net/~openstack</a><br>
> Post to : openstack@lists.launchpad.net<br>
> Unsubscribe : <a href="https://launchpad.net/~openstack">https://launchpad.net/~openstack</a><br>
> More help : <a href="https://help.launchpad.net/ListHelp">https://help.launchpad.net/ListHelp</a><br>
<br>
<br>
_______________________________________________<br>
Mailing list: <a href="https://launchpad.net/~openstack">https://launchpad.net/~openstack</a><br>
Post to : openstack@lists.launchpad.net<br>
Unsubscribe : <a href="https://launchpad.net/~openstack">https://launchpad.net/~openstack</a><br>
More help : <a href="https://help.launchpad.net/ListHelp">https://help.launchpad.net/ListHelp</a><br>
</div>
</span></font>
</body>
</html>